Treatment of hydrocarbon oils



Patented Apr. 26, 1932 UNITED STATES PATENT oFFifcE JAGQUE C. MORRELL AND GUSTAV EGLOFF, OF CHIGAGO, ILLINOIS, ASSIGNORS TO UNI- VERSAL OIL PRODUCTS COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF SOUTH DAKOTA TREATMENT or :aYnRocAnnoN OILS No Drawing.

This invention relates to the treatment of hydrocarbon oils and refers more particularly to the refining of the relatively low boiling hydrocarbon distillates.

In one of its specific aspects the invention embodies a process for the refining of cracked hydrocarbon oils and comprises subjecting such oils to treatment with sulphur dioxide and an oxygen containing gas, such 4? as air, oxygen, ozone preferably in the presence of steam and ferric sulphate.

The invention has especial application to the refining of the lighter hydrocarbon distillates in the vapor phase and is particularly useful in the refining in the vapor phase of the relatively low boiling products resulting from the conversion of hydrocarbon oils by subjecting the said vapors from the cracking process during or subsequent to fractionation to treatment with sulphur dioxide and oxygen containing gas such as air preferably in the presence of steam and in the presence of ferric sulphate.

The usual method of refining cracked distillates is to subject them to treatment with sulphuric acid and alkaline solutions, including plumbite solutions consisting of litharge dissolved in alkaline solutions in various combinations of treatment and subsequently to subject the acid treated product to redistillation usually in the presence of steam. The present invention permits the direct treatment of the hydrocarbon vapors from the cracking process, reducing the cost of reagents and eliminating the redistillation of Sulphur dioxide and air or other oxygen containing gas from any suitable source, alone Application filed January 29, 1831. Serial No. 512,209.

or in combination with steam, maybe introduced directly into the tower or treating vessel containing the ferric sulphate. In lieu of direct packing of the tower or treating vessel with the ferric sulphate an inert filling material such as Raschig rings, firebrick,

crushed rock, gravel, crushed ceramic material, and the like, suitably coated with a ferric sulphate, or a mixture of the same may be employed. Similarly, any device which permits the efiicient contacting of the vapors undergoing treatment with ferric sulphate may be employed.

The tower or treating vessel containing the ferric sulphate may be directly connected to a cracking unit or to a rerun or re distillation unit so that the vapors arising therefrom may be treated in the manner described.

It has been found desirable to neutralize the distillate immediately after condensation either by passing the condensate directly through a body of alkaline material, such as a solution of caustic soda, or by washing the distillate free of acidic materials with water and/or alkalies, such as a solution of caustic soda, ammonia or the like. The neutralizing agent may also be introduced into the vapor line leading to the'condenser or into the condenser itself.

The amount of sulphur dioxide employed may vary from a fraction of a poundto several pounds, based on a barrel of hydrocarbon distillate treated.

Various temperatures of treatment may be employed; for example, from 250600 F., more or less, and the pressures may be subatmospheric, atmospheric, or superatmospheric. While the results may vary with the temperatures employed, the pressures and,

temperatures are chosen so that the hydrocarbons are treated substantially in the vapor phase.

As specific examples of the operation of the process of my invention and of the results obtained, a California cracked distillate of approximately motor fuel boiling range is vaporized and subjected to treatment with sulphur dioxide and air in the presence of ferric sulphate. The vapors were passed at a suitable rate through the tower containing the zinc oxide and approximately three pounds of sulphur dioxide per barrel of distillate together with air is employed. The untreated product shows a gum content of approximately 500 mgs. per 100 cos. and a reddish brown color. The sulphur content is approximately 0.23. The treated product shows a gum content of approximately 30 mgs. per 100 ccs. and has a color of plus on the Saybolt colorimeter scale. The sulphur content may be reduced to approximately 0.15. The gum determinations are made by the copper dish method.

When the ferric sulphate is distributed over pumice stone similar results to those just described were obtained.

A mixed mid-continent and west Texas cracked distillate when treated in the vapor phase with sulphur dioxide and air employlng ferric sulphate as a contacting agent gives the following results: The untreated distillate shows a gum content of approximately 325 mgs. per ccs. and a light amber color. The treated distillate may be reduced in gum content to approximately 25 mgs. per 100 ccs. and a color of approximately 30 on the Saybolt colorimeter scale. The sulphur content may be reduced also.

Another California cracked distillate when treated with approximately three pounds of sulphur dioxide together with an excess of air in the presence of ferric sulphate shows the following results: The untreated distillate contains approximately 600 mgs. of gum per 100 cos. The treated distillate may contain approximately 50 mgs. per 100 ccs. The untreated distillate is a dark reddish amber incolor, and the treated distillate may have a color from 25 to 30 on the Saybolt colorimeter scale. The sulphur content is quite appreciably reduced.

any combination of the above refining agents, followed is desired, by distillation.

e claim as our invention:

A step in refining the overhead product resulting from the cracking of hydrocarbon With a mid-continent distillate containing 7 approximately 350 mgs. of gum per 100 ccs. and having a dark yellow color one may obtain a product containing approximately 30 mgs. of gum per 100 ccs. having a color of approximately 25-30 on the Saybolt colorimeter scale and with an appreciable reduction in sulphur content by treatment with sulphur dioxide and air in the presence of ferric sulphate employing approximately three pounds per barrel, based on the distillate treated.

The above examples are only illustrative and should not be construed as restrictions or limitations on the broad scope of the invention.

The treatment herein described may constitute the sole refining action on the oil, or it may constitute one step in a series of refining steps. It may be preceded by the usual treatments with refining agents such as sulphuric acid, caustic, soda, plumbite, filtering r earth or the like, and may be succeeded by 

